The present invention relates to a bearing in a manual transmission for transferring torque between at least a first guide surface on a swivel element, which can swivel and which is fixed along the bearing relative to the manual transmission, and between a second guide surface, which can move in the longitudinal direction relative to the bearing and which is supported with the swivel element so that it can swivel at least in the bearing, wherein the guide surfaces are spaced apart from each other by means of at least one roller body, which supports in one direction the first guide surface and in a different direction the second guide surface, which is configured like a roller, and which can roll in the longitudinal direction.
A bearing of the class-forming type is described in DE 40 20 160 A1. The bearing is arranged on a central selector or control shaft and a selector rocker. The supported element, in this case a swiveling selector shaft, carries another element of the manual transmission, in this case the selector rocker, in the swivel direction over the bearing. The selector rocker is therefore supported in the housing of the manual transmission so that it can swivel and is pivoted with its free end against the force of a spring element fixed to the housing. Therefore, at the selector shaft, the spring force acting on the lever of the selector rocker produces a desired counter torque of defined magnitude as a function of a predetermined swivel angle of the selector shaft or as a function of the path in radian measure at the rocker (torque-path course). This counter torque generates, e.g., on the manual selector lever, a desired noticeable increase in the shifting force over a predetermined shifting path (force-path course).
The selector shaft is movable relative to the manual transmission along its longitudinal axis and is arranged so that it can swivel and is supported so that it can slide along its longitudinal axis but is fixed in rotation by means of the bearing in a hub of the selector rocker. The selector rocker is supported so that it can rotate but is fixed to the manual transmission longitudinal to the selector shaft. Between the hub and the selector shaft, there are roller bodies located in the hub with as little radial play as possible for low-friction longitudinal motion of the selector shaft. In the circumferential direction, the roller bodies transfer torque through the bearing to the selector rocker or in the reverse direction. The roller bodies are balls or rollers and are supported during transfer of the torque on a selector shaft formed with a round cross section in longitudinal raceways on the shaft and corresponding counter raceways on the hub.
The production of a bearing shown in DE 40 20 160 A1 is relatively complicated to manufacture based on the grooves in the hub and in the selector shaft. For these bearings, especially for bearings with balls, the value of the maximum transferable torque is often too low due to limited available installation space for roller bodies of sufficient size and number. The level is determined by the maximum permissible Hertzian stress at the contact of the roller bodies installed in the bearing in interaction with their raceways.
For the previously mentioned reasons, DE 40 20 160 A1 alternatively provides that the selector shaft has a shape deviating from a circular cross section at least in the region of the close sliding fit in the bearing. In this case, this section of the selector shaft is formed as a right prism. The side walls of the hub facing the selector shaft with the guide surfaces for the roller bodies run parallel to the side surfaces of the prism. Between the side surface on the selector shaft and the opposing guide surface on the hub, there are rollers or needles as roller bodies. The roller bodies are guided relative to each other with a cage.
The transferable torque in such a bearing is relatively high, however, the process of manufacturing profiles for the hub and the selector shaft with a shape that is different from the circular shape on the close sliding fit is comparatively complicated. The raceways for the roller bodies are usually tempered. The steel selected for the selector shaft thus must be able to be tempered based on the requirements of the raceway. In addition, the handling of the relatively large selector shafts during the tempering process increases the resulting costs for the production of such a selector shaft.
It is difficult to adapt the torque-displacement courses on the selector shaft, and thus easy shifting forces, or force-displacement courses on the manual selector level to the requirements of the shifting ease in arrangements according to the state of the art. This is also based on the fact that the bearings of the selector shaft can be loaded only partially due to their configuration mentioned in the introduction.